Ionizing-radiation-responsive compositions, methods, and systems

ABSTRACT

A method, composition and system respond to ionizing radiation to adjust biological activity. In some approaches the ionizing radiation is X-ray or extreme ultraviolet radiation that produces luminescent responses that induce biologically active responses.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to and claims the benefit of theearliest available effective filing date(s) from the following listedapplication(s) (the “Related Applications”) (e.g., claims earliestavailable priority dates for other than provisional patent applicationsor claims benefits under 35 USC §119(e) for provisional patentapplications, for any and all parent, grandparent, great-grandparent,etc. applications of the Related Application(s)).

RELATED APPLICATIONS

For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation-in-part of U.S. patentapplication Ser. No. 11/975,702, entitled IONIZING-RADIATION-RESPONSIVECOMPOSITIONS, METHODS, AND SYSTEMS, naming Edward S. Boyden; Roderick A.Hyde; Muriel Y. Ishikawa; Edward K. Y. Jung; Nathan P. Myhrvold;Clarence T. Tegreene; Thomas A. Weaver; Charles Whitmer; Lowell L. Wood,Jr. and Victoria Y. H. Wood as inventors, filed 18 Oct. 2007 now U.S.Pat. No. 8,164,074.

The United States Patent Office (USPTO) has published a notice to theeffect that the USPTO's computer programs require that patent applicantsreference both a serial number and indicate whether an application is acontinuation or continuation-in-part. Stephen G. Kunin, Benefit ofPrior-Filed Application, USPTO Official Gazette Mar. 18, 2003, availableat http://www.uspto.gov/web/offices/com/sol/og/2003/week11/patbene.htm.The present Applicant Entity (hereinafter “Applicant”) has providedabove a specific reference to the application(s) from which priority isbeing claimed as recited by statute. Applicant understands that thestatute is unambiguous in its specific reference language and does notrequire either a serial number or any characterization, such as“continuation” or “continuation-in-part,” for claiming priority to U.S.patent applications. Notwithstanding the foregoing, Applicantunderstands that the USPTO's computer programs have certain data entryrequirements, and hence Applicant is designating the present applicationas a continuation-in-part of its parent applications as set forth above,but expressly points out that such designations are not to be construedin any way as any type of commentary and/or admission as to whether ornot the present application contains any new matter in addition to thematter of its parent application(s).

All subject matter of the Related Applications and of any and allparent, grandparent, great-grandparent, etc. applications of the RelatedApplications is incorporated herein by reference to the extent suchsubject matter is not inconsistent herewith.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts irradiation of an ionizing-radiation-responsivecomposition.

FIG. 2 depicts a photolabile material.

FIG. 3 depicts a photoisomerizable material.

FIGS. 4A-4C depict ionizing-radiation-responsive compositions.

FIGS. 5A-5C and 6A-6C depict configurations of a photosensitivebioactivity-adjusting material and a biologically active material.

FIG. 7 depicts irradiation of an ionizing-radiation-responsivecomposition.

FIGS. 8A-8G, 9A-9H, 10A-10B, 11A-11D, and 12 depictionizing-radiation-responsive compositions.

FIGS. 13-14 depict irradiation of an ionizing-radiation-responsivecomposition.

FIGS. 15-17 depict process flows.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise. The illustrative embodiments described in thedetailed description, drawings, and claims are not meant to be limiting.Other embodiments may be utilized, and other changes may be made,without departing from the spirit or scope of the subject matterpresented here.

FIG. 1 depicts an illustrative embodiment in which an ionizing radiationemitter 100 produces ionizing radiation 102. The ionizing radiationirradiates at least a portion of a region 104 that contains aluminescent material 110 and a photosensitive biologically activematerial 112. The region 104 might include, for example, a human oranimal patient or a portion thereof, such as the head, neck, limb,thorax, spine, abdomen, or pelvis; or a particular tissue, organ, orgland; or a particular lesion caused by disease or injury; or any otherarea selected for treatment. In the illustrative embodiment depicted inFIG. 1, the beam of ionizing radiation partitions the region 104 into anirradiated region 106 and a non-irradiated region 108. In the irradiatedregion 106, the luminescent material responds to ionizing radiation 102to produce optical energy 114, and the photosensitive biologicallyactive material responds to the optical energy 114 to becomebiologically active, as indicated schematically in FIG. 1 by the radiallines 116 (other embodiments provide other responses of thephotosensitive biologically active material; for example, thephotosensitive biologically active material may respond to the opticalenergy 114 to become biologically inactive, to partially increase ordecrease a level of biological activity, to change from a first mode ofbiological activity to second mode of biological activity, etc.). In thenon-irradiated region 108, the luminescent material does not receiveionizing radiation, so it does not produce optical energy to activatethe photosensitive biologically active material.

In general, the term “photosensitive biologically active material” canencompass any material having a biological activity that changes inresponse to optical energy. For example, the photosensitive biologicallyactive material can include a material that is biologically inactive andresponds to optical energy to become biologically active, a materialthat is biologically active and responds to optical energy to becomebiologically inactive, a material that has a first level of biologicalactivity and responds to optical energy to change to a second level ofbiological activity, a material that has a first mode of biologicalactivity and responds to optical energy to change to a second mode ofbiological activity, or any other material or combination of materialshaving any response to optical energy that may affect its biologicalactivity.

In some embodiments, the photosensitive biologically active material isa photosensitizer that responds to optical light by generating areactive oxygen species (such as singlet oxygen) or another cytotoxicagent. Photosensitizers are sometimes used to destroy cancerous ordiseased cells by a procedure known as photodynamic therapy (PDT).Generally this procedure involves: (1) administration of aphotosensitizing drug; (2) selective uptake or retention of thephotosensitizing drug in the target tissue or lesion; (3) delivery ofoptical light to the target tissue or lesion; (4) light absorption bythe photosensitizing drug to generate a cytotoxic agent that damages ordestroys the target tissue or lesion; and (5) metabolism or excretion ofthe photosensitizing drug to reduce sunlight sensitivity. Photodynamictherapy and photosensitizers and their uses are further described in S.A. Unger, “Photodynamic Therapy,” Buffalo Physician, Autumn 2004, 8-19;Paras N. Prasad, Introduction to Biophotonics, Wiley-Interscience, 2003,433-463; and Tuan Vo-Dinh et al, Biomedical Photonics Handbook, CRCPress, 2003, 36-1 to 38-16; which are herein incorporated by reference.Some examples of photosensitizers include porphyrins, chlorins,bacteriochlorins, benzoporphyrins, flavins, texaphyrins,phthalocyanines, naphthalocyanines, cationic dyes, halogenatedxanthenes, dendrimers, fullerenes, organometallic complexes, andsemiconductor nanoparticles; also, combinations or derivatives of thesevarious compounds, and pharmaceutical preparations thereof. Someapplications involve the administration of a photosensitizer metabolicprecursor; an example is 5-aminolaevulinic acid (ALA), whichendogenously generates the photosensitizer photoporphyrin IX.

In some embodiments, the photosensitive biologically active material caninclude a photolabile material. FIG. 2 is a schematic depiction of aphotolabile material 200, having a first component 201 and a secondcomponent 202 joined by a photolabile component 203. Those elementsdepicted with dashed lines are optional in some embodiments. Thematerial is responsive to optical energy in at least one wavelengthband, as depicted by the arrow 204 labeled with a wavelength λ, todivide the photolabile component into two fragments 205. Those of skillin the art use various terms to describe this response to opticalenergy, including for example “photolysis,” “photodissociation,”“photo-release,” and “photo-uncaging.” If the photolabile component 203is the only structure that couples the first component and the secondcomponent, then the material may be completely cleaved in response tooptical energy in the at least one wavelength band. If the material 200optionally includes a third component 206 joined to the first component201 and the second component 202 by non-photolabile components 207, thenthe structure is modified in response to optical energy in the at leastone wavelength band, but the material is not completely cleaved and thefirst and second components remain indirectly coupled. The modified orcleaved structure can have a biological activity that differs from thatof the unmodified or uncleaved structure.

Various photosensitive biologically active materials that includephotolabile materials are known to those skilled in the art. Somerepresentative examples are as follows; other embodiments will beapparent to those skilled in the art. Fay et al, “Photosensitive cagedmacromolecules,” U.S. Pat. No. 5,998,580, herein incorporated byreference, describes various peptides incorporating a photolabilemolecule (e.g. 2-nitrophenyl, 2-nitrobenzyloxycarbonyl, or α-carboxy2-nitrobenzyl) and responsive to optical energy to become biologicallyactive or inactive. Grissom et al, “Bioconjugates and delivery ofbioactive agents,” U.S. Pat. No. 6,777,237, herein incorporated byreference, describes an example of a bioactive agent bonded to a cobaltatom in an organocobalt complex, where the complex responds to light tocleave the bond between the bioactive agent and the cobalt atom, therebyreleasing the bioactive agent. Kehayova et al, “Phototriggered deliveryof hydrophobic carbonic anhydrase inhibitors,” Photochem. Photobiol.Sci. 1 (2002), 774-779, herein incorporated by reference, describes acarbonic anhydrase inhibitor bearing a photolabile cage compound,o-nitrodimethoxyphenylglycine (o-NDMPG) and responsive to optical lightto photo-uncage (and thereby activate) the inhibitor molecule. W.Neuberger, “Device and method for photoactivated drug therapy,” U.S.Pat. No. 6,397,102, herein incorporated by reference, describes a drugthat is encapsulated in or attached to a photolabile fullerene molecule;when the inactive drug-fullerene complex is subjected to selectiveirradiation, the complex is broken and the drug is released in an activeform. A. Momotake et al, “The nitrodibenzofuran chromophore: a newcaging group for ultra-efficient photolysis in living cells,” NatureMethods 30 (2006), 35-40, and W. H. Li, “Crafting new cages,” NatureMethods 30 (2006), 13-15, both herein incorporated by reference,describe a photolabile nitrodibenzofuran caging group. V. Tassel et al,“Photolytic drug delivery systems,” International Application No.PCT/US96/01333, and A. W. Lindall, “Catheter system for controllablyreleasing a therapeutic agent at a remote tissue site,” U.S. Pat. No.5,470,307, both herein incorporated by reference, describe a therapeuticor diagnostic agent bound to a polymer, metal, glass, silica, quartz, orother substrate by a photolabile linking agent (e.g. a 2-nitrophenyl,acridine, nitroaromatic, arylsulfonamide, or similar chromophore),responsive to optical light to release the therapeutic or diagnosticagent from the substrate. Guillet et al, “Drug delivery systems,” U.S.Pat. No. 5,482,719, herein incorporated by reference, describes in oneembodiment a polymer and a therapeutic compound, chemically bondedtogether through a photolabile covalent chemical linkage (e.g. aphotolabile peptide blocker compound), and responsive to light torelease the therapeutic compound from the polymer combination.

In some embodiments, the photosensitive biologically active material caninclude a photoisomerizable material. FIG. 3 is a schematic depiction ofa photoisomerizable material 300, having a first component 301 and asecond component 302 joined by a photoisomer component in a firstisomeric form 303. The material is responsive to optical energy in atleast a first wavelength band, as depicted by the arrow 204 labeled witha wavelength λ₁, to convert the photoisomer component to a secondisomeric form 305. The shape change depicted in the figure is aschematic representation of isomerization and is not intended to belimiting. In some embodiments the two isomeric forms of the photoisomercomponent are cis and trans isomers. In some embodiments the transitionfrom the first isomeric form to the second isomeric form isirreversible. In other embodiments the transition from the firstisomeric form to the second isomeric form is reversible, as indicated bythe dashed arrow 306. The reverse transition may occur in response tooptical energy in at least a second wavelength band (as indicated by thelabel λ₂) or the reverse transition may occur in response to a reductionor absence of optical energy at least the first wavelength band (asindicated by the label “dark”). The different isomeric forms of thephotoisomerizable material can have different biological activities.

Various photosensitive biologically active materials that includephotoisomerizable materials are known to those skilled in the art. Somerepresentative examples are as follows; other embodiments will beapparent to those skilled in the art. Volgraf et al, “Allosteric controlof an ionotropic glutamate receptor with an optical switch,” Nat. Chem.Biol. 2 (2006), 47-52; Banghart et al, “Light-activated ion channels forremote control of neuronal firing,” Nature Neuroscience 7 (2004),1381-1386; and Isacoff et al, “Photoreactive regulator of proteinfunction and methods of use thereof,” U.S. Patent ApplicationPublication No. US2007/0128662 A1, all of which are herein incorporatedby reference, describe photoisomerizable materials responsive to opticallight to regulate protein functions. Kumita et al, “Photo-control ofhelix content in a short peptide,” PNAS 97 (2000), 3803-3808, hereinincorporated by reference, describes a peptide modified to include anazobenzene photoisomer and responsive to optical energy to increase thehelix content of the peptide.

In some embodiments the photosensitive biologically active materialincludes a binding partner of a protein, wherein the photosensitivebiologically active material is responsive to optical energy to modifyan interaction between the binding partner and the protein. The proteinand binding partner might be, for example: a receptor and acorresponding receptor ligand (e.g. an agonist, inverse-agonist,antagonist, pore blocker, etc.); an enzyme and a corresponding enzymeligand (e.g. an allosteric effector, inhibitor, activator, etc.); or anyother protein, protein fragment, or protein complex and a correspondingligand (e.g. an element, molecule, peptide, etc.) capable of binding tothe protein, protein fragment, or protein complex and subsequentlyaffecting the behavior of the protein, protein fragment, or proteincomplex. In some embodiments the binding partner has a probability ofbinding to the protein that is changeable in response to optical energyin the at least one wavelength band. For example, the photosensitivebiologically active material may include a photolabile component thatcages or inhibits the binding partner; in response to optical energy,the photolabile component is removed and the binding partner can bind toits corresponding protein. As another example, the photosensitivebiologically active material may include a photoisomer, where theisomeric form of the photoisomer affects the ability or the bindingpartner to bind to its corresponding protein. Volgraf et al, Banghart etal, and Isacoff et al, as cited above, provide examples of a bindingpartner (e.g. a pore blocker or a receptor agonist) tethered to aphotoisomer, where isomerization causes the binding partner to changeits position relative to a binding site. In other embodiments a boundcombination of the protein and the binding partner has a level ofbiological activity that is changeable in response to optical energy inthe at least one wavelength band. For example, Eisenman et al,“Anticonvulsant and anesthetic effects of a fluorescent neurosteriodanalog activated by visible light,” Nature Neuroscience 10 (2007),523-530, herein incorporated by reference, describes afluorescently-tagged neurosteriod (NBD-allopregnanolone) that binds tothe GABA_(A) receptor and responds to optical light to potentiatereceptor function.

In some embodiments, the photosensitive biologically active materialincludes a combination of a biologically active material and aphotosensitive bioactivity-adjusting material, where the photosensitivebioactivity-adjusting material is responsive to optical energy toincrease, decrease, or otherwise affect the biological activity of thebiologically active material. For example, the photosensitivebioactivity-adjusting material may be disposed to at least partiallyinhibit biological activity of the biologically active material andresponsive to optical energy to at least partially uninhibit biologicalactivity of the biologically active material. Alternatively oradditionally, the photosensitive bioactivity-adjusting material may be amaterial having a first state causing at least a first degree ofinhibition of biological activity of the biologically active materialand a second state causing at most a second degree of inhibition ofbiological activity of the biologically active material, where the firstdegree of inhibition is greater than the second degree of inhibition,and where the photosensitive bioactivity-adjusting material isresponsive to optical energy in at least the first wavelength band to atleast partially convert from an unconverted state to a converted state,the unconverted state and converted state being uniquely selected fromthe group consisting of the first state and the second state. In someembodiments the conversion from the unconverted state to the convertedstate may be irreversible. In other embodiments the conversion from theunconverted state to the converted state may be reversible, and thereverse conversion (or reversion) from the converted state to theunconverted state may occur in response to optical energy in at least asecond wavelength band or in response to a reduction or absence ofoptical energy at least the first wavelength band. The biologicallyactive material may include any substance having a biological orpharmaceutical activity, including but not limited to analgesics,anti-infectives, antineoplastics (or other cytotoxic or chemotherapeuticagents), cardiovascular agents, diagnostic agents, dermatologicalagents, EENT agents, endocrine or metabolic agents, gastrointestinalagents, gynecological agents, hematological agents, immunologicalagents, neurological agents, psychotherapeutics, pulmonary agents,respiratory agents, or urological agents; also, vitamins, anti-oxidants,and other nutritional or nutriceutical agents. A biologically activematerial may or may not have an intrinsic response to optical energy tochange its biological activity, but the combination of a biologicallyactive material and a photosensitive bioactivity-adjusting material canconstitute a photosensitive biologically active material that isresponsive to optical energy. Throughout this document, the term“photosensitive biologically active material” is intended to encompassmaterials that are a combination of a biologically active material and aphotosensitive bioactivity-adjusting material, unless context dictatesotherwise.

FIGS. 4A-4C depict some exemplary configurations of anionizing-radiation-responsive composition 400 comprising a luminescentmaterial 110, a photosensitive bioactivity-adjusting material 404, and abiologically active material 410. These are illustrative configurationsonly, and are not intended to be limiting. FIG. 4A shows aphotosensitive bioactivity-adjusting material 404 disposed as aphotosensitive matrix material that occupies the interstices between, orotherwise encloses, embeds, or absorbs, a plurality of portions of abiologically active material 410. FIG. 4B shows a photosensitivebioactivity-adjusting material 404 disposed as a photosensitive layerthat encloses or envelops a biologically active material 410. FIG. 4Cshows a photosensitive bioactivity-adjusting material 404 disposed as asubstrate material having a surface that attaches, adsorbs, or otherwisecouples to a biologically active material 410. Each configuration inFIGS. 4A-4C depicts a core-shell structure having a core of luminescentmaterial 110, but this is an illustrative disposition of the luminescentmaterial and is not intended to be limiting. In other embodiments of theionizing-radiation-responsive composition 400, the luminescent materialis unattached to either the biologically active material or thephotosensitive bioactivity-adjusting material, at least partiallyattached to one or the other, or variously disposed in configurationsthat combine all three materials. Some configurations of an ionizingthat combine a luminescent material and a photosensitive biologicallyactive material (where the latter may itself comprise a biologicallyactive material and a photosensitive bioactivity-adjusting material) aredescribed elsewhere. In each configuration in FIGS. 4A-4C, thephotosensitive bioactivity-adjusting material is responsive to opticalenergy in at least a first wavelength band, as depicted by the arrow 204labeled with a wavelength λ₁, to at least partially allow release of thebiologically active material 410. In some embodiments the response tooptical energy is irreversible; in other embodiments the response isreversible, as indicated by the dashed arrow 304 depicting a reversion.The reversion may occur in response to optical energy in at least asecond wavelength band (as indicated by the label λ₂) or the reversionmay occur in response to a reduction or absence of optical energy atleast the first wavelength band (as indicated by the label “dark”).

In some embodiments, the photosensitive bioactivity-adjusting materialmay include a substrate material having a surface that attaches,adsorbs, or otherwise couples to a biologically active material, andresponsive to optical energy to release the biologically active materialfrom the surface (optionally, embodiments include a linking agent, e.g.a bifunctional photolytic linker, that connects the substrate materialand the biologically active material, and that responds to opticalenergy to disconnect the substrate material and the biologically activematerial, e.g. by photolysis). For example, embodiments may usematerials such as those in Van Tassel et al and in Lindall (both citedpreviously and herein incorporated by reference). Various substratematerials include natural polymers, synthetic polymers, silica, glass,quartz, metal, and any other materials capable of directly or indirectlybinding to the biologically active material (in some embodiments theluminescent material, or another constituent of theionizing-radiation-responsive composition, may serve as the substratematerial). Various linking agents include 2-nitrophenyl groups,acridines, nitroaromatics, arylsulfonamides, or similar photolyticagents capable of directly or indirectly binding to both the substratematerial and the biologically active material.

In some embodiments, the photosensitive bioactivity-adjusting materialincludes a material that responds to optical energy to change adiffusion characteristic of the material, which may affect a rate ofdiffusion of the biologically active material through the photosensitivebioactivity-adjusting material. For example, embodiments may usematerials such as those in Fink et al, “Photoactivated drug therapy,”U.S. Patent Application Publication No. 2003/0216284, hereinincorporated by reference; in this reference, optical energy (in theform of a resonant mode of a cavity) causes a change in a diffusioncharacteristic of at least one component of the cavity, in turn causingrelease of a pharmaceutical from the cavity (in one embodiment describedtherein, the at least one component is a polymeric material and theresonance causes heating whereby the polymeric material exceeds a glasstransition temperature).

In some embodiments, the photosensitive bioactivity-adjusting materialmay include a material that responds to optical energy to undergo ashape change (e.g. an expansion, contraction, or bending); the shapechange may correspond to a change of a diffusion characteristic, or theshape change may affect some other means for release of the biologicallyactive material (e.g. a shrinkage may create a pressure that expels thebiologically active material, or a bending may open a gate-likestructure to release the biologically active material), or both. Forexample, embodiments may use materials such as those in Rosenthal et al,“Triggered release hydrogel drug delivery system,” U.S. Pat. No.7,066,904, herein incorporated by reference; this reference describescatheters that include a polymer or polymer gel disposed to incorporateand immobilize a drug, and responsive to optical light to swell orcontract such that the drug is released. Embodiments may use alight-sensitive copolymer or copolymer gel, where a first component ofthe light-sensitive copolymer or copolymer gel is polyacrylamide,poly(N-isopropylacrylamide), hydroxyethyl methacrylate, dihydroxypropylmethacrylate, a copolymer or mixture thereof, or the like, and a secondcomponent of the light-sensitive copolymer or copolymer gel is alight-sensitive compound that induces swelling (as with malachite greenderivatives, leucocyanides, leucohydroxides, or similar compounds, e.g.as described in “Photoinduced phase transition of gels,” Macromolecules23 (1990), 1517-1519, herein incorporated by reference, and in Guilletet al, supra) or that induces contraction (as with chlorophyllin,rhodamine, or similar compounds, e.g. as described in “Phase transitionin polymer gels induced by visible light,” Nature 346 (1990), 345-347,herein incorporated by reference) of the light-sensitive copolymer orcopolymer gel in response to optical energy.

In some embodiments, the photosensitive bioactivity-adjusting materialmay include a material that responds to optical energy to at leastpartially photodegrade, photodissociate, or photodisintegrate (suchterms may be used interchangeably); the photodegradation,photodissociation, or photodisintegration may correspond to a change ofa diffusion characteristic, or affect some other means for release ofthe biologically active material (e.g. a mechanical disintegration ofthe photosensitive bioactivity-adjusting material may cause an exposureor dispersal of the biologically active material), or both. For example,embodiments may use photochemically degradable polymers such as thosedescribed in Guillet et al, supra (e.g. copolymers of ethylenicallyunsaturated monomers with unsaturated ketones).

In some embodiments, the photosensitive bioactivity-adjusting materialmay include a material that responds to optical energy to change itshydrophobicity, hydrophilicity, or amphiphilicity; this change maycorrespond to a change of a diffusion characteristic, or affect someother means for release of the biologically active material (e.g. thechange may compel a phase separation of immiscible hydrophilic andhydrophobic components), or both. For example, embodiments may usepolymers that convert photochemically from a hydrophobic form to ahydrophilic form, such as those described in Guillet et al, supra (e.g.polymers incorporating a t-butyl ketone group in a side chainimmediately adjacent to the polymer backbone).

With reference now to FIGS. 5A-5C, some illustrative examples of thepreceding embodiments are shown, including a photosensitivebioactivity-adjusting material 404 and a biologically active material410. For purposes of clarity, a luminescent material is not depicted inthese examples, but this omission is not intended to be limiting, andembodiments provide a luminescent material that is enclosed, attached,or otherwise disposed in a vicinity of the photosensitivebioactivity-adjusting material and/or the biologically active material.FIG. 5A depicts an example of a photosensitive bioactivity-adjustingmaterial 404 disposed as a photosensitive matrix material enclosing abiologically active material 410, and responsive to optical energy in atleast a first wavelength band (as depicted by the arrow 204 labeled witha wavelength λ₁) to expand, the expansion causing a release (e.g. bydiffusion) of the biologically active material 410. FIG. 5B depicts anexample of a photosensitive bioactivity-adjusting material 404 disposedas a photosensitive matrix material enclosing a biologically activematerial 410, and responsive to optical energy in at least a firstwavelength band (as depicted by the arrow 204 labeled with a wavelengthλ₁) to contract, the contraction causing a release (e.g. by pressureexpulsion) of the biologically active material 410. Alternatively oradditionally, in relation to FIG. 5B, the photosensitive matrix materialmay be initially disposed to at least partially allow release (e.g. bydiffusion) of the biologically active material, and responsive tooptical energy to contract, the contraction at least partiallyinhibiting release (e.g. by reducing diffusion) of the biologicallyactive material. FIG. 5C depicts an example of a photosensitivebioactivity-adjusting material 404 disposed as a photosensitive matrixmaterial enclosing a biologically active material 410, and responsive tooptical energy in at least a first wavelength band (as depicted by thearrow 204 labeled with a wavelength λ₁) to at least partiallyphotodegrade, photodissociate, or photodisintegrate, thereby releasingthe biologically active material 410 (and optionally releasing fragments500 of the photosensitive bioactivity-adjusting material). In someembodiments, a process depicted in FIGS. 5A-5C is irreversible; in otherembodiments the process is reversible, as indicated by the dashed arrow304 depicting a reverse process. The reverse process may occur inresponse to optical energy in at least a second wavelength band (asindicated by the label λ₂) or the reverse process may occur in responseto a reduction or absence of optical energy at least the firstwavelength band (as indicated by the label “dark”).

In some embodiments, the photosensitive bioactivity-adjusting materialmay include a photosensitive layer (or a plurality thereof) disposed toat least partially enclose or envelop at least a portion of thebiologically active material, and responsive to optical energy to atleast partially allow release of the biologically active material. Theterm “layer” is intended to encompass a variety of structures includingmembranes, films, coatings, shells, coverings, patches, etc., as well asmulti-layered structures. The term “layer” further encompasses micelles,vesicles, liposomes, lipid membranes, and other monolayers, bilayers,etc. as assembled from phospholipids, amphiphilic block copolymers, orother amphiphiles. In some embodiments the photosensitive layer mayinclude one or more materials such as those described supra, e.g. amaterial that responds to optical energy to change a diffusioncharacteristic, a material that responds to optical energy to undergo ashape change (e.g. an expansion, contraction, or bending), a materialthat responds to optical energy to at least partially photodegrade,photodissociate, or photodisintegrate (thereby rupturing, perforating,or otherwise disrupting the layer), or a material that responds tooptical energy to change its hydrophobicity, hydrophilicity, oramphiphilicity. Embodiments may use a photosensitive layer that embedsone or more light-sensitive channel proteins such as those described inKocer et al, “A light-actuated nanovalve derived from a channelprotein.” Science 309 (2005), 755-758, and Kocer et al, “Modified MscLprotein channel,” U.S. Patent Application Publication No.US2006/0258587, both herein incorporated by reference; these referencesdescribe a modified channel protein embedded in a membrane andresponsive to optical energy to irreversibly open (or reversiblyopen/close) a pore in the membrane. Other embodiments may use materialssuch as those described in P. Ball. “Light pumps drugs fromnanoparticles,” Nanozone News, Jun. 9, 2005, herein incorporated byreference; e.g., a liposomal membrane (or similarmonolayer/bilayer/etc.) that is at least partially comprised ofphotoisomerizable phospholipids (or similar photoisomizableamphiphiles), or that incorporates photoisomerizable cholesterol (orother photoisomerizable molecules that can attach to or embed within themembrane, e.g. integral membrane proteins), or both, whereby thephotosensitive layer responds to optical energy to change porosity (e.g.open pores), become ruptured or perforated, or otherwise allow releaseof the enclosed biologically active material.

With reference now to FIGS. 6A-6C, some illustrative examples of thepreceding embodiments are shown, including a biologically activematerial 410 and a photosensitive bioactivity-adjusting material 404disposed as a photosensitive layer that encloses the biologically activematerial. For purposes of clarity, a luminescent material is notdepicted in these examples, but this omission is not intended to belimiting, and embodiments provide a luminescent material that isenclosed, attached, or otherwise disposed in a vicinity of thephotosensitive bioactivity-adjusting material and/or the biologicallyactive material. FIG. 6A depicts an example of a photosensitive layerthat is responsive to optical energy in at least a first wavelength band(as depicted by the arrow 204 labeled with a wavelength λ₁) to becomeruptured or perforated, whereby the biologically active material isreleased through one or more ruptured or perforated areas 600. FIG. 6Bdepicts an example of a photosensitive layer embedding one or morepore-like structures (e.g. channel proteins) in a closed configuration602, the one or more pore-like structures being responsive to opticalenergy in at least a first wavelength band (as depicted by the arrow 204labeled with a wavelength λ₁) to convert to an open configuration 604,whereby the biologically active material is released. FIG. 6C depicts anexample of a photosensitive layer that embeds one or morephotoisomerizable molecules (e.g. photoisomerizable phospholipids orcholesterols) in a first isomeric form 606, the one or morephotoisomerizable molecules being responsive to optical energy in atleast a first wavelength band (as depicted by the arrow 204 labeled witha wavelength λ₁) to convert to a second isomeric form 608, therebychanging a diffusion, porosity, or other characteristic of thephotosensitive layer to allow release of the biologically activematerial. In some embodiments, a process depicted in FIGS. 6A-6C isirreversible; in other embodiments the process is reversible, asindicated by the dashed arrows 304 depicting a reverse process. Thereverse process may occur in response to optical energy in at least asecond wavelength band (as indicated by the label λ₂) or the reverseprocess may occur in response to a reduction or absence of opticalenergy at least the first wavelength band (as indicated by the label“dark”).

Treating a tissue or lesion with a photosensitive biologically activematerial typically involves locally irradiating the tissue or regionwith optical light (or otherwise locally applying some form of opticalenergy). Optical light or optical energy generally includeselectromagnetic radiation in the visible portion of the electromagneticspectrum (e.g. having wavelengths in the range of 380 nm to 750 nm orfrequencies in the range of 400 to 800 THz) as well as neighboringregions of the electromagnetic spectrum (including but not limited tofar-infrared, infrared, near-infrared, near-ultraviolet, ultraviolet,and extreme-ultraviolet). The terms “optical light” and “optical energy”also encompass quantized electromagnetic radiation (i.e. photons) andnon-radiative forms of electromagnetic energy (e.g. standing waves,evanescent fields, Forster resonance energy transfer (FRET), etc.).Optical light in the red and near-infrared region of the spectrum (themost penetrating) has a penetration depth of about 2 to 6 mm, dependingon the wavelength and the tissue. The challenge of delivering opticallight to a non-superficial region is therefore a substantial limitationof existing therapies, often involving interstitial, intracavitary, orintravascular placement of optical fibers capped with diffuser tips andcoupled to a laser light source. Some embodiments offer an alternatemode of optical light delivery, wherein the optical light or opticalenergy is locally emitted by a luminescent material in response toionizing radiation, which can be highly penetrative and preciselydelivered to a region of interest.

Ionizing radiation is radiation having an ability to ionize an atom ormolecule. Radiation may be referred to as ionizing radiation whether ornot the radiation causes ionization in any particular embodiment or useof the aspects described herein. For example, ionizing radiation mayhave energy sufficient to ionize a first kind of atom or molecule, butinsufficient to ionize a second kind of atom or molecule. Therefore, insome embodiments where the ionizing radiation interacts only with thesecond kind of atom or molecule, it may not cause ionization. Theionizing radiation can be electromagnetic radiation such as extremeultraviolet (EUV) rays, soft or hard x-rays, or gamma-rays, or chargedparticle radiation in the form of electrons, protons, or ions (e.g.,carbon and neon).

The ionizing radiation emitter 100 can include a high-voltage vacuumtube or field emitter, EUV or x-ray laser, discharge- or laser-producedplasma device, synchrotron, particle accelerator, or similar device; or,a radioactive material comprising one or more radioactive isotopes; or,a combination of such materials and/or devices. If the ionizingradiation emitter includes a radioactive isotope, the ionizing radiationmay be a direct radioactive decay product (e.g. an electron, position,or gamma ray), or a product of a subsequent process (e.g. bremsstrahlungor characteristic x-rays, gamma rays from electron-positronannihilation, or electrons created by photoelectric, Auger, or pairproduction processes).

If the region 104 includes a human or animal patient or a portionthereof, the ionizing radiation emitter can be positioned outside,adjacent to, or inside the patient. Examples of ionizing radiationemitters that can be positioned outside the patient include x-rayradiograph instruments, computed tomography (CT) instruments,fluoroscopes, radiosurgery instruments (such as the Cyberknife or GammaKnife), teletherapy or external beam radiotherapy devices, and proton orion beam devices. Examples of ionizing radiation emitters that can bepositioned adjacent to or inside the patient include catheter-mountedminiaturized x-ray tubes, sealed radioactive sources that are applied asmolds or implanted by surgery, catheter, or applicator; andradiopharmaceuticals that are directly injected or ingested (theseinclude beta-active isotopes of iodine, phosphorus, etc. as used forradiotherapy, gamma-active isotopes of gallium, technetium, etc. as usedfor imaging, and positron-emitting isotopes of carbon, fluorine, etc. asused for positron-emission tomography (PET)).

In various embodiments the ionizing radiation 102 can be substantiallymonochromatic, quasi-monochromatic, or polychromatic. Examples ofsubstantially monochromatic or quasi-monochromatic ionizing radiationinclude characteristic x-rays, beta and gamma rays from radioactivedecay, undulator synchrotron rays, and accelerated proton or ion beams.Examples of polychromatic ionizing radiation include wiggler and bendingmagnet synchrotron rays and bremsstrahlung rays. The energy spectrum andintensity of the ionizing radiation can be modified, shaped, or variedin time by various means known to those skilled in the art; for example,by adjusting the cathode-anode voltage in an x-ray vacuum tube, or usingx-ray optics devices such as Bragg monochromators and attenuationfilters.

Various embodiments utilize different space and time configurations ofthe ionizing radiation 102. The particular depictions of the ionizingradiation that are shown in the figures are schematic and not intendedto be limiting. For example, the ionizing radiation may be substantiallyisotropic (i.e. radiating in most or all directions), fan-shaped,cone-shaped, collimated in a thin ray, etc.; these and other irradiationpatterns can be achieved by various means known to those skilled in theart, e.g. deployment of lenses, mirrors, zone plates, baffles, slots, orapertures, or positioning of leaves in a multileaf collimator (MLC). Inthose embodiments where the ionizing radiation is deployed as a beam,the orientation and position of the beam can be varied with respect tothe target region 104, for example by mounting the emitter and/or thetarget on a moveable pivot, track, arm, or gantry, or manually adjustingthe position of an intravascular catheter with an emitter on its distalend. The extent of the irradiated region 106 is determined by theenergy, intensity, shape, orientation, and position of the ionizingradiation beam, and by the scattering and absorption properties of theregion 104. For example, depth-dose characteristics of typicalradiotherapy x-ray and proton beams are described in A. Boyer et al,“Radiation in the Treatment of Cancer,” Physics Today, September 2002,which is herein incorporated by reference. Typically, hard x-rays aremore penetrating than soft x-rays, and protons have a longer range thanelectrons, with a characteristic Bragg peak at the end of their range.In some embodiments the irradiation may comprise multiple ionizingradiation beams, either emitted in a time sequence by a single emitter,or emitted by a plurality of emitters, or both. The multiple beams mayhave different energies, intensities, orientations, and/or positions;alternatively, a continuously or stroboscopically emitting beam (or aplurality thereof) may continuously or intermittently change its energy,intensity, orientation, and/or position. In some embodiments, techniquessuch as those used in radiotherapy and stereotactic radiosurgery can beutilized to deliver an effective amount of radiation to a region oftherapeutic interest (such as a tumor) while reducing radiation damageto neighboring tissues; these techniques include 3D conformalradiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT), asdescribed in A. Boyer, “The Physics of Intensity-Modulated RadiationTherapy,” Physics Today, September 2002, which is herein incorporated byreference.

The luminescent material 110 is a material that is responsive toionizing radiation to produce optical energy. Generally, the term“luminescent material” encompasses all materials that respond toradiation (ionizing or non-ionizing) to produce optical energy (the term“phosphor” is sometimes used with equivalent meaning), and it producesthe optical energy by a process called luminescence. The term“luminescence” encompasses various processes including fluorescence,phosphorescence, and afterglow. Many luminescent materials are known tothose skilled in the art, with various characteristics of absorption,emission, and efficiency, for example as described in G. Blasse and B.C. Grabmaier, Luminescent Materials, Springer-Verlag, Berlin 1994, whichis herein incorporated by reference.

When the incident radiation is ionizing radiation, the luminescentmaterial is often referred to as a scintillator. Scintillators cancomprise organic or inorganic materials, in the form of crystals(including micro- and nano-scale crystals), particles (including micro-and nano-scale particles), powders, composites, ceramics, glasses,plastics, liquids, and gases. Some scintillation materials and detectorsare described in M. Nikl, “Scintillation detectors for x-rays,” Meas.Sci. Technol. 17 (2006), R37-R54 and in C. W. E. van Eijk, “Inorganicscintillators in medical imaging,” Phys. Med. Biol. 47 (2002), R85-R106,which are both herein incorporated by reference. Scintillators aresometimes referred to as phosphors, especially in applications where thematerial is deployed as a powder screen, viz. lamp phosphors, cathoderay tube (CRT) phosphors, x-ray intensifying screen phosphors, and x-raystorage phosphors (c.f. G. Blasse and B. C. Grabmaier, supra; storagephosphors are additionally described in H. von Seggern, “Photostimulablex-ray storage phosphors: a review of present understanding,” Braz. J.Phys. 29 (1999), 254-268, and in W. Chen, “Nanophase luminescenceparticulate material,” U.S. Pat. No. 7,067,072, which are both hereinincorporated by reference).

A luminescent material generally comprises one or more sensitizersand/or one or more activators embedded in a host material, although insome cases an activator also plays the role of sensitizer, or the hostmaterial plays the role of sensitizer or activator or both. Theluminescence process generally proceeds as follows: (1) incidentradiation is absorbed by the sensitizer; (2) the energy is transferredthrough the host material to the activator, raising it to an excitedstate; and (3) the activator returns to the ground state by emission ofoptical radiation. A first example is the lamp phosphor Ca₅(PO₄)₃F:Sb³⁺,Mn²⁺, where an Sb³⁺ sensitizer/activator and an Mn²⁺ activator areembedded as dopants in a fluorapatite host material. A second example isdescribed in Y. L. Soo et al, “X-ray excited luminescence and localstructures in Tb-doped Y₂O₃ nanocrystals,” J. Appl. Phys. 83 (1998),5404-5409, which is herein incorporated by reference; in this material,the yttrium in the host nanocrystal is a sensitizer, and the dopantterbium is a sensitizer/activator with green luminescence. A thirdexample is a class of organometallic lanthanide-cryptate scintillatorsdescribed in G. Blasse et al, “X-ray excited luminescence ofsamarium(III), europium(III), gadolinium(III), and terbium(III) 2.2.1cryptates,” Chem. Phys. Lett. 158 (1989), 504-508, which is hereinincorporated by reference; in these materials, the cryptate bypyridineis a sensitizer, and the caged lanthanide is a sensitizer/activator. Afourth example is the x-ray phosphor described in W. Chen et al, “Theorigin of x-ray luminescence from CdTe nanoparticles in CdTe/BaFBr:Eu²⁺nanocomposite phosphors,” J. Appl. Phys. 99 (2006), 034302, which isherein incorporated by reference; in this material, the BaFBr hostmaterial is a sensitizer, the Eu²⁺ dopant is a sensitizer/activatoremitting at 390 nm, and the CdTe nanoparticle is an activator emittingat a wavelength of 541, 610, or 650 nm for a nanoparticle size of 2, 4,or 6 nm, respectively.

The absorption of incident radiation by a sensitizer (or a host materialcomponent acting as a sensitizer) generally varies with the energy ofthe incident radiation according to a characteristic absorptionspectrum; some embodiments provide a plurality of sensitizers (or aplurality of host material components acting as sensitizers, or acombination thereof) having a plurality of characteristic absorptionspectra. The emission of radiation by an activator (or a host materialcomponent acting as an activator) generally varies with the energy ofthe emitted radiation according to a characteristic emission spectrum;some embodiments provide a plurality of activators (or a plurality ofhost material components acting as activators, or a combination thereof)having a plurality of characteristic emission spectra. In someembodiments, selective transfer of energy from the plurality ofsensitizers to the plurality of activators (e.g. as characterized by amatrix of energy transfer efficiencies) can be used to provide selectivewavelength/energy conversion of incident radiation to emitted radiation;viz, incident radiation in a first (second) absorption energy bandsubstantially excites a first (second) sensitizer, the excitation energyis substantially transferred to a first (second) activator, and thefirst (second) activator substantially emits radiation in a first(second) emission energy band.

The overall effectiveness of the luminescent material for convertingincident ionizing radiation into optical energy is determined in part bythe absorption characteristics of the material. Absorption of ionizingradiation in matter, and detection thereof, are described in W. M. Yaoet al, Review of Particle Physics, J. Phys. G: Nucl. Part. Phys. 33(2006), 258-292, which is herein incorporated by reference. If theionizing radiation consists of charged particles (including electrons,protons, and ions), the charged particles lose energy through Coulombinteractions with the electrons in the material; ionization is thedominant Coulomb process except at ultrarelativistic energies. Amaterial with a high electron density (i.e. a high mass density) istypically a better absorber of charged particle radiation. If theionizing radiation consists of photons (ultraviolet rays, x-rays, orgamma rays), absorption is dominated by the photoelectric effect at lowenergies, then by Compton and pair production processes at successivelyhigher energies. For Compton and pair production processes, theabsorption is proportional to electron density, and a material with ahigh electron density (i.e. a high mass density) is a better absorber.For the photoelectric effect, the absorption cross section isapproximately proportional to Z³/E³, where E is the energy of theincident photon and Z is the atomic number of the target atom. Amaterial with a high effective atomic number Z_(eff) (i.e. as averagedover its constituent elements) is therefore a better photoelectricabsorber. Overall, a material with a high mass density, and a higheffective atomic number Z_(eff), is a better absorber of both chargedparticle energy and photon energy.

Moreover, the photoelectric cross section is characterized bydiscontinues, known as absorption edges, as thresholds for ionization ofvarious atomic shells are reached. The absorption edges for successiveshells with principal quantum numbers n=1, n=2, n=3, etc. arerespectively called the K-edge, L-edge, M-edge, etc. In someembodiments, the ionizing radiation includes one or more substantiallymonochromatic beams of photons, each having an energy E just above aphotoelectric absorption edge of the luminescent material; or, theionizing radiation includes a polychromatic beam of photons, where theenergy spectrum of the polychromatic beam consists essentially of aplurality of peaks coinciding with a plurality of absorption edges forthe luminescent material. In these embodiments the ionizing radiation issubstantially absorbed by the luminescent material, and the absorptionby neighboring tissues may be mitigated, especially in those embodimentswhere the absorption edges of the luminescent material are distinct fromthose of the neighboring tissues.

In some embodiments, the luminescent material has a host material thatincludes a heavy metal selected from the group consisting of alkalinemetals, alkaline earth metals, transition metals, poor metals, andmetalloids. The term “heavy metal” is taken to include any metal ormetalloid element having an atomic number greater than or equal to 37(i.e. elements in periods 5, 6, or 7). The term “alkaline metals” istaken to include elements in group 1 of the periodic table (excludinghydrogen), i.e. lithium, sodium, potassium, rubidium, cesium, andfrancium. The term “alkaline earth metals” is taken to include elementsin group 2 of the period table, i.e. beryllium, magnesium, calcium,strontium, barium, and radium. The term “transition metals” is taken toinclude elements in groups 3 to 12 of the periodic table. The term “poormetals” is taken to include aluminum, gallium, indium, tin, thallium,lead, and bismuth. The term “metalloids” is taken to include boron,silicon, germanium, arsenic, antimony, tellurium, and polonium.

In some embodiments, the emission spectrum of the luminescent materialshould substantially overlap or coincide with the absorption spectrum ofthe photosensitive biologically active material. The emission spectrumis partially determined by intrinsic properties of the activatorcomponent of the luminescent material, and by its local environment inthe host material (e.g. the activator's crystal field, coordination,chelation, etc.). If the luminescent material comprises nanoparticles ornanocrystals, a quantum size effect can occur, whereby the spatialconfinement of the valence electron wavefunctions causes smallerparticles of the same composition to have emission spectra that areshifted to smaller wavelengths (e.g. as observed in W. Chen et al,supra).

In some embodiments, the luminescent material can include quantum dots.These are nanocrystals comprised of various semiconductor materials,which can include but are not limited to group IV elements (C, Si, Ge),group IV binary compounds (SiC, SiGe), III-V binary compounds (AlSb,AlAs, AlN, AlP, BN, BP, BAs, GaSb, GaAs, GaN, GaP, InSb, InAs, InN, InP,etc.), III-V ternary compounds (AlGaAs, InGaAs, AlInAs, AlInSb, GaAsN,GaAsP, AlGaN, AlGaP, InGaN, InAsSb, InGaSb, etc.), III-V quaternarycompounds (AlGaInP, AlGaAsP, InGaAsP, AlInAsP, AlGaAsN, InGaAsN,InAlAsN, etc.), III-V quinary compounds (GaInNAsSb), II-VI binarycompounds (CdSe, CdS, CdTe, ZnO, ZnSe, ZnTe, etc.), II-VI ternarycompounds (CdZnTe, HgCdTe, HgZnTe, HgZnSe, etc.), I-VII binary compounds(CuCl, etc.), IV-VI binary compounds (PbSe, PbS, PbTe, SnS, SnTe, etc.),IV-VI ternary compounds (PbSnTe, Tl₂SnTe₅, Tl₂GeTe₅, etc.), V-VI binarycompounds (Bi₂Te₃, Bi₂S₃ etc.), II-V binary compounds (Cd₃P₂, Cd₃As₂,Cd₃Sb₂, Zn₃P₂, Zn₃As₂, Zn₃Sb₂, etc.), miscellaneous oxides (TiO₂, Cu₂O,CuO, UO₂, UO₃, etc.), other miscellaneous inorganic compounds (PbI₂,MoS₂, GaSe, CuInGaSe, PtSi, BiI₃, HgI₂, TlBr, etc.), and organicsemiconductors. In some embodiments, the quantum dots comprise heavierelements such as mercury, lead, bismuth, or polonium, to enhance theabsorption of ionizing radiation. The quantum dots can also be doped,e.g. as described in Erwin et al, “Doping semiconductor nanocrystals,”Nature 436 (2005), 91-94, which is herein incorporated by reference;accordingly some embodiments provide quantum dots that are doped withheavier elements, such as the lanthanides or other period 6 elements,again to enhance the absorption of ionizing radiation. In someembodiments the quantum dots may have a core-shell structure, with thecore consisting of a first semiconductor material, and a shellconsisting of a second semiconductor material. Additionally, one or morecoatings and/or functional groups may be applied or attached to thequantum dot, to improve solubility, durability, suspensioncharacteristics, bioactivity, etc. as discussed infra. Desired opticalproperties of the quantum dot (e.g. quantum efficiency, Stokes shift,emission wavelength) can be further adjusted by controlling the size,shape, and structure of the quantum dot through various fabricationprocesses known to those skilled in the art (for example, W. Chen,supra, describes how to control the emission wavelength by adjusting thenanoparticle size; accordingly, the emission wavelength can be matchedto a peak in the absorption spectrum of the photosensitive biologicallyactive material).

FIG. 7 depicts another illustrative embodiment and use in which anionizing radiation emitter 100 emits an ionizing radiation 102. Theionizing radiation irradiates at least a portion of a region 104 thatcontains a ionizing-radiation-responsive composition 400, which is abound composition comprising a luminescent material 110 and aphotosensitive biologically active material 112. As in FIG. 1, theluminescent material responds to ionizing radiation to produce opticalenergy, and the photosensitive biologically active material responds tooptical energy to become biologically active, as indicated schematicallyby the radial lines 116 (other embodiments provide other responses ofthe photosensitive biologically active material; for example, thephotosensitive biologically active material may respond to the opticalenergy to become biologically inactive, to partially increase ordecrease a level of biological activity, to change from a first mode ofbiological activity to second mode of biological activity, etc.). Whenthe luminescent material and the photosensitive biologically activematerial are bound together as in FIG. 7, the optical energy may betransferred from the luminescent material to the photosensitivebiologically active material by either radiative or nonradiativeprocesses. An example of a nonradiative energy transfer process isForster resonance energy transfer (FRET), as described in G. Blasse andB. C. Grabmaier, supra.

FIG. 7 illustrates the ionizing-radiation-responsive composition incross-section as having a core-shell structure, with the core consistingof luminescent material and a shell consisting of photosensitivebiologically active material. This is only a schematic depiction of thebound composition and is not intended to be limiting. Someconfigurations of the bound composition include but are not limited tothose depicted in cross section in FIGS. 8A-8G. In variousconfigurations the two materials form a core-shell structure with onematerial comprising the core and the other material comprising either acomplete shell or one or more spots or patches on the surface of thecore; a binary aggregate structure with one or more adjoining regions ofthe two materials; a host-inclusion structure, where one material is aninclusion or dopant of the other material; and other configurations.Various techniques known to those skilled in the art can be used toproduce or synthesize these bound compositions. For example, W. Chen andJ. Zhang, “Using nanoparticles to enable simultaneous radiation andphotodynamic therapies for cancer treatment,” J. Nanosci. Nanotech. 6(2006), 1159-1166, which is herein incorporated by reference describes aconjugation of porphyrins to nanoparticles using L-cysteine as abifunctional ligand. M. Wieder et al. “Intracellular photodynamictherapy with photosensitizer-nanoparticle conjugates: cancer therapy,using a ‘Trojan horse,’” Photochem. Photobiol. Sci. 5 (2006), 797-734herein incorporated by reference, describes a derivatization of aphthalocyanine photosensitizer with a thiol moiety to provide a directlinkage to a nanoparticle surface via self-assembly. Other functionalligands and conjugation methods are described in G. T. Hermanson,Bioconjugate Techniques, Academic Press (1996). L. Shi et al, “Singletoxygen generation from water-soluble quantum dot-organic dyenanocomposites,”, J. Am. Chem. Soc. 128 (2006), 6278-6279, hereinincorporated by reference, describes a synthesis of a nanocompositeconsisting of meso-tetra(4-sulfonatophenyl)porphine dihydrochloride(TSPP), a photosensitizer, bound to CdTe nanocrystals via electrostaticinteraction.

In some embodiments, the ionizing-radiation-responsive compositionfurther comprises an adjuvant matrix or coating material. Someconfigurations of the bound composition include but are not limited tothose depicted in cross section in FIGS. 9A-9H, where the unshadedregion 900 represents the adjuvant matrix or coating material. Ingenerals the adjuvant matrix or coating material is a material that isselected and disposed to improve various biological and pharmaceuticalcharacteristics of the ionizing-radiation-responsive composition,including but not limited to solubility, durability, suspensionstability, bioactivity, biocompatibility, chemical affinity, biologicalaffinity, porosity, permeability, non-toxicity, and radiationresponsiveness. The adjuvant matrix or coating material may also providea mechanical means to embed, confine, attach, adhere, or bind togetherat least a portion of the constituents of theionizing-radiation-responsive composition, or at least partially sustainthe proximity of at least a portion of the consistuents, eitherpermanently or temporarily (an example of the latter is a slow-releasepolymer). Generally, a matrix material is a material that at leastpartially embeds one or more other materials, or at least partiallyoccupies interstices in the spatial configuration of one or more othermaterials, and a coating material is a material that at least partiallysurrounds or envelops one or more other materials; however, those ofskill in the art will recognize that the terms “matrix material” and“coating material” encompass other configurations, and that in somecontexts the terms have overlapping meaning (e.g. a matrix material thatis also a coating material, or vice versa). The use of the term“adjuvant” is intended in this context to denote that the adjuvantmatrix or coating material is not substantially a photosensitivebiologically active material, or substantially a photosensitivebioactivity-adjusting material, nor substantially a luminescent materialresponsive to ionizing radiation to produce optical energy to activate aphotosensitive biologically active material or a photosensitivebioactivity-adjusting material; rather, the adjuvant matrix or coatingis a material that potentiates, moderates, improves, or otherwisemodifies the individual or cumulative biological or pharmaceuticalcharacteristics of these other constituents of theionizing-radiation-responsive composition. An adjuvant matrix or coatingmaterial is therefore understood to be distinct from a photosensitivebioactivity-adjusting material disposed as a photosensitive matrix orcoating. The intended meaning of “matrix” or “coating” (e.g.photosensitive matrix or adjuvant matrix) will be apparent from thecontext in which said term is used

Various adjuvant matrix and coating materials, and methods of deployingsuch materials in a bound composition, are known to those skilled in theart. Some representative examples are as follows; other embodiments willbe apparent to those skilled in the art. A first example is a porousglass, such as that used to embed CdSe/ZnS quantum dot alpha particlescintillators as described in S. E. Letant and T. F. Wang, “Study ofporous glass doped with quantum dots or laser dyes under alphairradiation,”, Appl. Phys. Lett. 88 (2006), 103110, herein incorporatedby reference. A second example is a silica shell, which can enclose aphotosensitizer as described in Wang et al, “Nanomaterials and singletoxygen photosensitizers: potential applications in photodynamictherapy,” J. Mater. Chem. 14 (2004), 487-493; E. Bergey and P. Prasad,“Small spheres, big potential,” OE Magazine, Jul. 2003, 26-29; and P.Prasad et al, “Ceramic based nanoparticles for entrapping therapeuticagents for photodynamic therapy and method of using same,” U.S. PatentApp. Pub. No. US 2004/0180096; which publications are hereinincorporated by reference. The silica shell can be made hydrophobic,hydrophilic, or both, as appropriate for biological context, and theporosity of the silica shell can be tailored, e.g. to allow permeationof singlet oxygen from a photosensitizer. Silica shells can also be usedto coat quantum dots (cf. X. Michalet, “Quantum dots for live cells, invivo imaging, and diagnostics,” Science 307 (2005), 538-544, hereinincorporated by reference), magnetic nanoparticles (c.f. L. Levy et al,“Nanochemistry: synthesis and characterization of multifunctionalnanoclinics for biological applications,” Chem. Mater. 14 (2002),3715-3721; B. A. Holm et al, “Nanotechnology in biomedicalapplications,” Mol. Cryst. Liq. Cryst. 374 (2002), 589-598; and P.Prasad et al, “Magnetic nanoparticles for selective therapy,” U.S. Pat.No. 6,514,481; which publications are herein incorporated by reference),and other particles or nanoparticles, and they can be functionalizedwith PEG groups for enhanced biocompatibility, e.g. as described in T.Zhang et al, “Cellular effect of high doses of silica-coated quantum dotprofiled with high throughput gene expression analysis and high contentcellomics measurements,” Nano Letters 6 (2006), 800-808, hereinincorporated by reference. A third example is a micellular agent such asPEG-PE, which can be used, for example, to encapsulate a photosensitizer(cf. A. Roby, et al, “Solubilization of poorly soluble PDT agent,meso-tetraphenylporphin, in plain or immunotargeted PEG-PE micellesresults in dramatically improved cancer cell killing in Vitro,” Eur. J.Pharm. Biopharm. 62 (2006), 235-240, herein incorporated by reference)or a quantum dot (c.f. B. Dubertret et al, “In vivo imaging of quantumdots encapsulated in phospholipid micelles,” Science 298 (2002),1759-1762, herein incorporated by reference). A fourth example is amatrix material comprising polyacrylamide hydrogel, sol gel silica, orcross-linked decyl methacrylate; nanoparticles utilizing these matrixmaterials are described in E. Monson et al, “PEBBLE nanosensors for invitro bioanalysis,” Biomedical Photonics Handbook, CRC Press, 2003,59.1-59.14; “Nanotechnology tackles brain cancer,” Monthly Feature,December 2005, NCI Alliance for Nanotechnology in Cancer; and “Waterynanoparticles deliver anticancer therapy,” Nanotech News, Mar. 5, 2007,NCI Alliance for Nanotechnology in Cancer; which publications are hereinincorporated by reference. A fifth example is a chelant material (eithera natural chelant such as a porphyrin or porphyrin derivative, or asynthetic chelant such as ethylenediaminetetraacedit acid (EDTA) ordiethylenetriaminepentaacetic acid (DTPA)) or cryptand material (such asbypiridine), which materials can form a coordination complex to enclosevarious substrates including metals and cations. A sixth example is afullerene or a fullerene derivative (e.g. a carbon nanotube orbuckyball), where the interior volume can be used to contain variousmaterials; for example, B. Sitharaman et al, “Superparamagneticgadonanotubes are high-performance MRI contrast agents,” Chem. Commn.(2005), 3915-3917, herein incorporated by reference, describes a carbonnanotube loaded with Gd³⁺ ions as an MRI contrast agent.

Because a photosensitive biologically active material can be undesirablyactivated by ambient optical energy such as sunlight, special proceduresare sometimes necessary to avoid undesirable activation during storage,administration, treatment, and post-treatment. For example, patientstreated with the photosensitizing drug porfimer sodium are instructed toavoid sunlight or bright indoor light for at least 30 days aftertreatment. In some embodiments, the ionizing-radiation-responsivecomposition includes an optically-inhibiting material disposed to atleast partially block coupling of optical energy to the photosensitivebiologically active material. In an embodiment, the optically-inhibitingmaterial is disposed to selectively block coupling of optical energyfrom sources other than the luminescent material. In such an embodiment,the ionizing-radiation-responsive composition can become biologicallyactive when irradiated with ionizing radiation, but theoptically-inhibiting material may at least partially prevent thecomposition from becoming biologically active when irradiated withoptical energy. This can simplify storage, administration, and treatmentprocedures, and mitigate any ambient light photosensitivity of thepatient. In some embodiments the optically-inhibiting material maycomprise one or more thin metallic layers, optionally configured in amesh or porous structure. Lower-Z metallic elements such as beryllium,aluminum, or titanium may be utilized to provide optical blockingwithout substantial attenuation of ionizing radiation such as x-rays. Inother embodiments the optically-inhibiting material may comprisechromophores that are embedded in the adjuvant matrix or coatingmaterial to enhance absorption of optical energy in a wavelength rangecorresponding to an absorption band of the photosensitive biologicallyactive material. For example, organic dye molecules can be added to apolymer matrix or coating, or various metals (such as cobalt, gold,selenium, copper, etc. and salts, oxides, etc. thereof) can be added toa silica matrix or coating. In other embodiments theoptically-inhibiting material may comprise a polymeric photonic band gapmaterial (e.g. as described in Fink et al, “Polymeric photonic band gapmaterials,” U.S. Pat. No. 6,433,931, herein incorporated by reference)having a band gap that at least partially coincides with an absorptionband of the photosensitive biologically active material.

In some embodiments the ionizing-radiation-responsive compositionfurther comprises a biotargeting agent conveying a selective biologicalaffinity to the ionizing-radiation-responsive composition. Someconfigurations of the bound composition include but are not limited tothose depicted in cross section in FIGS. 10A and 10B, in which anionizing-radiation-responsive material 1000 (comprising a luminescentmaterial and a photosensitive biologically active material, andoptionally including other materials, e.g. an adjuvant matrix or coatingmaterial) is linked to or coated wraith a biotargeting agent 1010. Thedepictions are schematic and not intended to be limiting. In FIG. 10A,the biotargeting agent 1010 is depicted as having a y-shape, which maysuggest an exemplary embodiment in which the biotargeting agent is anantibody; but this is a symbolic depiction that encompasses allbiotargeting agents, including but not limited to: proteins andglycoproteins, monoclonal and polyclonal antibodies, lectins, receptorligands (including but not limited to vitamins, hormones, toxins, andanalogues or fragments thereof), peptides and polypeptides, aptamers,polysaccharides, sugars, and various other bioactive ligands andmoieties. Various bioconjugation methods are known to those skilled inthe art to deploy these biotargeting agents as a component of theionizing-radiation-responsive composition. For example, W. Chen and J.Zhang, supra describes a use of nanoparticle-conjugated folic acid as atumor-specific ligand. E. Bergey and P. Prasad, supra, L. Levy et al,supra, and P. Prasad et al, supra, describe an exemplary conjugation ofsilica-coated nanoparticles with peptides, polypeptides, or leutinizinghormone-releasing hormone (LH-RH). Various illustrative bioconjugationsof quantum dots are described in R. Hardman, “A toxicologic review ofquantum dots: toxicity depends on physicochemical and environmentalfactors,” Environmental Health Perspectives 114 (2006), 165-172, hereinincorporated by reference; S. Weiss et al, “Semiconductor nanocrystalprobes for biological applications and process for making and using suchprobes,” U.S. Pat. No. 6,207,392, herein incorporated by reference; andX. Michalet, supra. B. Storrie et al, “B/B-like fragment targeting forthe purposes of photodynamic therapy and medical imaging,” U.S. Pat. No.6,631,283, herein incorporated by reference, illustrates the conjugationof a targeting fragment of a toxin molecule or lectin to aphotosensitizing or imaging agent. A. Roby et al, supra, and B.Dubertret et al, supra, describe bioconjugations of micelles withantibodies and DNA, respectively. H. Dees and T. Scott, “Method forimproved imaging and photodynamic therapy,” U.S. Pat. No. 6,493,570,herein incorporated by reference, describes a derivatization of ahalogenated xanthene photosensitizer with various targeting moieties.

Some embodiments of the invention provide a first bound composition thatincludes a photosensitive biologically active material and a firstaffinity agent, and a second bound composition that includes aluminescent material and a second affinity agent. The first and secondaffinity agents are any two agents (which may be identical) having atendency to induce a proximity (e.g. in situ) of the photosensitivebiologically active material and the luminescent material, whereby thephotosensitive biologically active material may respond to opticalenergy produced by the luminescent material. In some embodiments thefirst and second affinity agents may include, respectively, first andsecond biotargeting agents having first and second selective biologicalaffinities, where the first and second selective biological affinitiesare at least partially overlapping (e.g. the first and secondbiotargeting agents each have at least some common affinity for aparticular tissue, lesion, organ, or other region, whereby thephotosensitive biologically active material and the luminescent materialcan be brought into proximity in situ). In other embodiments the firstand second affinity agents may, include, respectively, first and secondbinding partners selected from a pair of binding partners. Bindingpartners are pairs of molecules (or functional groups) having anaffinity to bind together. Some examples include: an antigen and acorresponding antibody or fragment thereof; a hapten and a correspondinganti-hapten; biotin and avidin or streptavadin; folic acid and folatebinding protein; a hormone and a corresponding hormone receptor; alectin and a corresponding carbohydrate, and enzyme and a correspondingcofactor, substrate, inhibitor, effector, etc.; vitamin B12 andintrinsic factor; complementary nucleic acid fragments (including DNA,RNA, and PNA (peptide nucleic acid) sequences), an antibody and ProteinA or G; a polynucleotide and a corresponding polynucleotide bindingprotein; other proteins and corresponding ligands; also, variouscovalent binding pairs such as sulfhydryl reactive groups, aminereactive groups, carbodiimide reactive groups, etc. Various methods areknown to those skilled in the art to deploy such binding partners inbound compositions. For example, Amaratunga et al, “Pharmaceuticals forenhanced delivery to disease targets,” U.S. Patent Application Pub. No.US2005/0260131, herein incorporated by references, describes pairs ofcompounds conjugated to complementary oligopeptide sequences (e.g. PNAsequences). Pomato et al, “In vivo binding pair pretargeting,” U.S. Pat.No. 5,807,534, herein incorporated by reference, describes methods thatdeploy an enzyme and a corresponding enzyme inhibitor as a binding pairfor in-situ pretargeting of an effector molecule (e.g. a radiometal).Croker et al, “Sol-gel coated glass microspheres for use in bioassay,”U.S. Patent Application Pub. No. US 2007/0117089, herein incorporated byreference, describes glass microspheres with a sol-gel coating thatcomprises a bioactive probe, where the bioactive probe can include onebinding partner selected from a pair of binding partners.

Some examples of the preceding embodiments are depicted in FIGS.11A-11D. These are schematic depictions of exemplary configurations, andare not intended to be limiting. In FIG. 11A, a first bound compositioncomprises a luminescent material 110 and a first biotargeting agent1101, and a second bound composition comprises a photosensitivebiologically active material 112 and a second biotargeting agent 1102(which may be the same as or different than the first biotargetingagent). FIG. 11B depicts an example in which the first and second boundcompositions of FIG. 11A attach to a common substrate 1103 by way of thebiotargeting agents 1101 and 1102, whereby the luminescent material andthe photosensitive biologically active material are brought intoproximity. The common substrate 1103 could be, for example, a tumorcell, a macromolecule (such as a protein), or some other feature forwhich the biotargeting agents 1101 and 1102 share an affinity. Thebiotargeting agents 1101 and 1102 are depicted as having a “y”-shape,which may suggest an exemplary embodiment in which the biotargetingagents are antibodies, and the common substrate 1103 is depicted ashaving a notched surface, which may suggest an exemplary embodiment inwhich the substrate is a cell that presents antigens on its surface, butthese are symbolic depictions that are intended to encompass all mannerof biotargeting agents and all manner of targets thereof. In FIG. 11C, afirst bound composition comprises a luminescent material 110 and a firstbinding partner 1110 selected from a pair of binding partners, and asecond bound composition comprises a photosensitive biologically activematerial 112 and a second binding partner 1112 selected from the pair ofbinding partners. In FIG. 11D, the first and second binding partners arebound together, whereby the luminescent material and the photosensitivebiologically active material are brought into proximity. The bindingpartners 1110 and 1112 are depicted as having a complementary “lock” and“key” shapes, which may suggest an exemplary embodiment in which thebinding partners are a protein and a corresponding protein ligand, butthis is a symbolic depiction that is intended to encompass all manner ofbinding partners and binding action thereof.

FIG. 12 depicts in cross section an embodiment of theionizing-radiation-responsive composition. The figure shows anillustrative configuration and is not intended to be limiting; otherconfigurations will be apparent to those skilled in the art. In thisconfiguration, the ionizing-radiation-responsive composition includes acore comprising a luminescent material 110, surrounded by an inner shellcomprising a photosensitive biologically active material 112 and anouter shell comprising an adjuvant matrix or coating material 900. Abiotargeting agent 1010 is attached to the outer shell. The embodimentfurther comprises a tagant material 1200. In the configuration depictedin FIG. 12, the tagant material is distributed as patches on the surfaceof the photosensitive biologically active material, but this is only anillustrative configuration and other configurations will be apparent tothose skilled in the art. For example, the tagant material may bedeposited on the outer surface of the bound composition, embedded in theinterior of the bound composition, etc. In general, a tagant material isa material that facilitates detection, imaging, or dosimetry of theionizing-radiation-responsive composition in situ, or that facilitatesimaging, sensing, assay, or other measurement of the in situenvironment. In a first embodiment, the tagant material may include aradioactive material, e.g. a gamma-active isotope of thallium,technetium, etc. that can be imaged with a SPECT camera or similarinstrument. In a second embodiment, the tagant material may include aradiocontrast agent, e.g. a high-Z material (such as iodine, xenon,barium, or a lanthanide) that strongly absorbs or scatters imagingx-rays. In a third embodiment, the tagant material may include an MRIcontrast agent, e.g. a gadolinium chelate or a magnetic nanoparticle. AnMRI contrast agent can also function as a sensor, for example byconjugating the contrast agent to a sensing moiety such as acalcium-binding calmodulin protein (c.f. T. Atanasijevic et al,“Calcium-sensitive MRI contrast agents based on superparamagnetic ironoxide nanoparticles and calmodulin,” PNAS 103 (2006), 14707-14712). In afourth embodiment, the tagant material may include a fluorescentmaterial, e.g. an organic dye, an inorganic dye, or a quantum dot. Thefluorescent material can also function as a sensor or indicator dye; anexample is the ruthenium-based dye [Ru(dpp)₃]²⁺, which has an intensitydecrease due to excited state quenching in the presence of molecularoxygen. Some examples of fluorescent dyes, sensor/indicator dyes, andquantum dot labels are described in T. Vo-Dinh et al, BiomedicalPhotonics Handbook, CRC Press, 2003, 56-1 to 56-20 and 58-1 to 58-14,herein incorporated by reference. E. Monson, supra, describes howvarious reference and indicator dyes can be incorporated into ananoparticle matrix.

FIG. 13 depicts another illustrative embodiment and use in which anionizing radiation emitter 100 produces ionizing radiation 102. Theionizing radiation irradiates at least a portion of a region 104 thatcontains an ionizing-radiation-responsive composition 200. As in FIG. 1and FIG. 7, the luminescent material responds to ionizing radiation toproduce optical energy, and the photosensitive biologically activematerial responds to optical energy to become biologically active (otherembodiments provide other responses of the photosensitive biologicallyactive material; for example, the photosensitive biologically activematerial may respond to the optical energy to become biologicallyinactive, to partially increase or decrease a level of biologicalactivity, to change from a first mode of biological activity to secondmode of biological activity, etc.). In the present embodiment, theionizing-radiation-responsive composition additionally responds toionizing radiation to produce scattered or luminescent radiation 1300. Afirst radiation detector 1302 is disposed to receive at least a portionof the scattered or luminescent radiation, and a second radiationdetector 1304 is disposed to receive at least a portion of the ionizingradiation that is transmitted or forward scattered through the region104. Other embodiments may include only the first radiation detector1302 or only the second radiation detector 1304. The scattered orluminescent radiation 1300 might include, for example, Compton-scatteredx-rays, pair production gamma rays, characteristic x-rays, or opticalfluorescence. In those embodiments wherein theionizing-radiation-responsive composition further comprises a tagantmaterial, the scattered or luminescent radiation can originate from thetagant material. The first radiation detector 1302 can include, forexample, one or more optical, x-ray, or gamma-ray sensors, optionallyconfigured as a planar or tomographic imaging system (such as a CCDcamera, optical tomograph, gamma camera, fluoroscope, PET scanner, SPECTscanner, or CT device). The second radiation detector 1304 can include,for example, one or more ionizing, radiation sensors (e.g. asemiconductor, phosphor, or scintillator detector), optionallyconfigured as a planar or tomographic system (ibid).

The embodiment depicted in FIG. 13 further comprises a controller unit1306 that is coupled to the ionizing radiation emitter, the firstradiation detector, and the second radiation detector. The controllerunit is configured to operate the ionizing radiation emitter, e.g. toactivate or deactivate the emitter (or some portion thereof), change itsmechanical position and orientation, and modulate the spectrum,intensity, beam shape, time sequence, etc. of the ionizing radiation.The controller unit is also configured to operate the first and/orsecond radiation detectors, e.g. to activate or deactivate eitherdetector, change its mechanical position and orientation, vary theimaging or detection settings (such as the gain, spectral range, orfield of view), and receive detection or imaging data. The controllerunit can receive data from the first and/or second radiation detectors,determine a correlated photoactivated dosage of the photosensitivebiologically active material, compare the correlated photoactivateddosage to a target photoactivated dosage, and adjust the operation ofthe ionizing radiation emitter to improve the correspondence between thecorrelated photoactivated dosage and the target photoactivated dosage.Additionally or alternatively, the controller unit can receive data fromthe first and/or second radiation detectors, which data comprises a mapor image of the target region, and generate a radiation dosage profilecorresponding to the map or image of the target region. For example, theionizing-radiation-responsive composition may have a selectivebiological affinity for a particular tissue, tumor, or lesion, andthereby serve as an imaging contrast agent to reveal the spatial extentof the particular tissue, tumor, or lesion. Optionally the controllerincludes an interface module, which may include one or more user inputdevices (keyboards, pointing devices, microphones, etc.), one or moreuser output devices (video displays, speakers, etc.), one or morenetwork interfaces (e.g. to access a computer network or database), orany combination thereof.

FIG. 14 depicts another illustrative embodiment and use in which anionizing radiation emitter 100 produces ionizing radiation 102. Theionizing radiation irradiates at least a portion of a region 104 thatcontains an ionizing-radiation-responsive composition 200. Theluminescent material responds to the ionizing radiation to produceoptical energy, and the photosensitive biologically active materialresponds to optical energy to become biologically active (otherembodiments provide other responses of the photosensitive biologicallyactive material; for example, the photosensitive biologically activematerial may respond to the optical energy to become biologicallyinactive, to partially increase or decrease a level of biologicalactivity, to change from a first mode of biological activity to secondmode of biological activity, etc.). The present embodiment furthercomprises a probe radiation emitter 1400, which emits probe radiation1402 that irradiates at least a portion of the region 104. The spatialextents of the ionizing radiation 102 and the probe radiation 1402 maybe disjoint, as depicted in FIG. 14, or they may at least partiallyoverlap. The ionizing-radiation-responsive composition responds to theprobe radiation to produce scattered or luminescent radiation 1300. Afirst radiation detector 1302 is disposed to receive at least a portionof the scattered or luminescent radiation, a second radiation detector1304 is disposed to receive at least a portion of the ionizing radiationthat is transmitted or forward scattered through the region 104, and athird radiation detector 1404 is disposed to receive at least a portionof the probe radiation that is transmitted or forward scattered throughthe region 104. Other embodiments may include any one or any two of thethree radiation detectors shown in FIG. 14. The probe radiation emitter1400 might include, for example, an ionizing radiation emitter, anoptical radiation emitter (especially one that operates atdeeper-penetrating red or near-infrared wavelengths), or an RF antennafor nuclear magnetic resonance (when used in combination with an NMRmagnet system, not shown). The scattered or luminescent radiation 1300might include, for example, Compton-scattered x-rays, pair productiongamma rays, characteristic x-rays, optical fluorescence, or NMR dipoleradiation. In those embodiments wherein theionizing-radiation-responsive composition further comprises a tagantmaterial, the scattered or luminescent radiation can originate from thetagant material. The first radiation detector 1302 and the thirdradiation detector 1404 can include, for example, or one or moreoptical, x-ray, or gamma-ray sensors, optionally configured as a planaror tomographic imaging system (such as a CCD camera, optical tomograph,gamma camera, fluoroscope, PET scanner, SPECT scanner, or CT device).The first radiation detector can include one or more RF antennas,optionally configured as part of a magnetic resonance imaging system.The second radiation detector 1304 can include, for example, one or moreionizing radiation sensors (e.g. a semiconductor, phosphor, orscintillator detector), optionally configured as a planar or tomographicsystem (ibid).

The embodiment depicted in FIG. 14 further comprises a controller unit1306 that is coupled to the ionizing radiation emitter, the proberadiation emitter, and the three radiation detectors. The controllerunit is configured to operate the ionizing radiation and probe radiationemitters, e.g. to activate or deactive each emitter (or some portionthereof), change its mechanical position and orientation, and modulatethe spectrum, intensity, beam shape, time sequence, etc. of the emittedradiation. The controller unit is also configured to operate theradiation detectors, e.g. to activate or deactivate a detector, changeits mechanical position and orientation, vary the imaging or detectionsettings (such as the gain, spectral range, or field of view), andreceive detection or imaging data. The controller unit can receive datafrom any or all of the radiation detectors, determine a correlatedphotoactivated dosage of the photosensitive biologically activematerial, compare the correlated photoactivated dosage to a targetphotoactivated dosage, and adjust the operation of the ionizingradiation emitter to improve the correspondence between the correlatedphotoactivated dosage and the target photoactivated dosage. Additionallyor alternatively, the controller unit can receive data from any or allof the radiation detectors, which data comprises a map or image of thetarget region, and generate a radiation dosage profile corresponding tothe map or image of the target region. For example, theionizing-radiation-responsive composition may have a selectivebiological-affinity for a particular tissue, tumor, or lesion, andthereby serve as an imaging contrast agent to reveal the spatial extentof the particular tissue, tumor, or lesion. Optionally the controllerincludes an interface module, which may include one or more user inputdevices (keyboards, pointing devices, microphones, etc.), one or moreuser output devices (video displays, speakers, etc.), one or morenetwork devices (e.g. to access a computer network or database), orsimilar devices and combinations thereof.

An illustrative embodiment is depicted as a process flow diagram in FIG.15. This process flow may characterize, for example, the operation ofthe controller unit 1306 depicted in FIGS. 13 and 14. Flow 1500 includesstep 1510—identifying a first process that at least partially convertsionizing radiation to an amount of optical energy. For example, ionizingradiation such as gamma rays or x-rays may be converted to opticalenergy by a luminescent material such as a scintillator or phosphorparticle. Flow 1500 further includes step 1520—identifying a secondprocess that at least partially converts the amount of optical energy tobiological activity. For example, a photosensitive biologically activematerial may respond to optical energy to become biologically active, ora photosensitive bioactivity-adjusting material may respond to opticalenergy to allow release of a biologically active material. Flow 1500further includes step 1530—responsive to the identifying a first processand the identifying a second process, determining an amount of ionizingradiation whereby a selected amount of biological activity is producedby a combination of the first process and the second process. Forexample, the first process may be characterized by an efficiency orcross section for conversion of ionizing radiation to optical energy(including spectral and in-situ dependencies thereof) and/or by aspatial distribution of a luminescent material that may accomplish thefirst process; the second process may be characterized by an efficiencyor sensitivity for conversion of optical energy to biological activity(including spectral and in-situ dependencies thereof) and/or by aspatial distribution of a photosensitive biologically active materialthat may accomplish the second process; these characterizations of thefirst process and the second process can be used to determine an amountof ionizing radiation which should be delivered to obtain a selectedamount of biological activity. The amount of ionizing radiation mayinclude a specification of an irradiation energy spectrum, time profile,or spatial profile. Flow 1500 further includes step 1540—irradiating atleast one region with the determined amount of ionizing, radiation. Forexample, an ionizing radiation emitter (e.g. a teletherapy device or CTinstrument) may be operated to delivered the determined amount ofionizing radiation (optionally according to a specified time, space, andor energy profile). Flow 1500 optionally includes step 1550—detecting anamount of ionizing radiation that is transmitted or forward scatteredthrough at least a portion of the at least one region. For example, anionizing radiation detector (e.g. a semiconductor, phosphor, orscintillator detector, optionally configured as a planar or tomographicsystem) may be operated to detect the transmitted or forward-scatteredionizing radiation. Flow 1500 optionally further includes step1555—determining an amount of biological activity corresponding to thedetected amount of ionizing radiation. For example, there may be acorrelation between the detected amount of transmitted or forwardscattered ionizing radiation and the actual amount of biologicalactivity caused by the irradiation in step 1540. Alternatively oradditionally, the detected amount of transmitted or forward scatteredionizing radiation malt reveal characteristics of the in-situenvironment (e.g. a spatial extent of a particular tissue, tumor, orlesion) whereon the amount of biological activity may depend (e.g. thebiological activity is specific to a particular tissue, tumor, orlesion). Flow 1500 optionally further includes step 1580—adjusting theirradiating to obtain the selected amount of biological activity. Forexample, the ionizing radiation emitter may be adjusted (e.g. byactivating or deactivating all or part of the emitter, changing itsmechanical position or orientation, or modifying the spectrum,intensity, beam shape, time sequence, etc. of the ionizing radiation),whereby a discrepancy between the selected amount of biological activity(as used in step 1530 to determine an amount of ionizing radiation toadminister) and the determined amount of biological activity (e.g. asobtained in step 1555, 1564, or 1576) may be at least partially removedor reduced.

Another illustrative embodiment is depicted as a process flow diagram inFIG. 16. This process flow may characterize, for example, the operationof the controller unit 1306 depicted in FIGS. 13 and 14. Flow 1600includes steps 1510, 1520, 1530, and 1540, as described above. Flow 1600optionally includes step 1560—identifying a third process that at leastpartially converts ionizing radiation to detectable radiation in atleast one radiation mode, where the conversion by the third process atleast partially corresponds to the conversion of ionizing radiation tobiological activity by the combination of the first process and thesecond process. For example, an agent that accomplishes the firstprocess and/or the second process (e.g. a luminescent material or aphotosensitive biologically active material or a combination thereof),or a tagant material paired with such an agent, may respond to ionizingradiation to produce scattered or luminescent radiation (e.g.Compton-scattered x-rays, pair production gamma rays, characteristicx-rays, or optical fluorescence). Flow 1600 optionally further includesstep 1562—detecting an amount of radiation in the at least one radiationmode. For example, a radiation detector (e.g. an optical, x-ray, orgamma-ray sensor, optionally configured as a planar or tomographicimaging system such as a CCD camera, gamma camera, fluoroscope, etc.)may be operated to detect radiation in the at least one radiation mode.Flow 1600 optionally further includes step 1564—determining an amount ofbiological activity corresponding to the detected amount of radiation inthe at least one radiation mode. For example, there may be a correlationbetween the detected amount of radiation in the at least one radiationmode and the actual amount of biological activity caused by theirradiation in step 1540. Alternatively or additionally, the detectedamount of radiation in the at least one radiation mode may revealcharacteristics of the in-situ environment (e.g. a spatial extent of aparticular tissue, tumor, or lesion) whereon the amount of biologicalactivity may depend (e.g. the biological activity is specific to aparticular tissue, tumor, or lesion). Flow 1500 optionally furtherincludes step 1580, as described above.

Another illustrative embodiment is depicted as a process flow diagram inFIG. 17. This process flow may characterize, for example, the operationof the controller unit 1306 depicted in FIGS. 13 and 14. Flow 1700includes steps 1510, 1520, 1530, and 1540, as described above. Flow 1700optionally includes step 1570—identifying a third process that at leastpartially converts radiation in at least a first radiation mode toradiation in at least a second radiation mode, where the conversion bythe third process at least partially corresponds to the conversion ofionizing radiation to biological activity by the combination of thefirst process and the second process. For example, an agent thataccomplishes the first process and/or the second process (e.g. aluminescent material or a photosensitive biologically active material ora combination thereof), or a tagant material paired with such an agent,may respond to radiation in at least the first radiation mode (e.g.ionizing radiation, optical radiation, or RF radiation—the latteroptionally originating from an RF antenna deployed as part of an NMRsystem) to produce scattered or luminescent radiation in at least thesecond radiation mode (e.g. Compton-scattered x-rays, pair productiongamma rays, characteristic x-rays, optical fluorescence, or NMR dipoleradiation). Flow 1700 optionally further includes step 1572—irradiatingat least a portion of the at least one region with an amount ofradiation in at least the first radiation mode. For example, a proberadiation emitter (e.g. ionizing radiation emitter, an optical radiationemitter, or an RF antenna used in combination with an NMR magnet system)may be operated to deliver the amount of radiation in at least the firstradiation mode. Flow 1700 optionally further includes step1574—detecting an amount of radiation in at least the second radiationmode. For example, a radiation detector (e.g. an optical, x-ray, orgamma-ray sensor, optionally configured as a planar or tomographicimaging system such as a CCD camera, gamma camera, fluoroscope, etc.; orone or more RF antennas, optionally configured as part of a magneticresonance imaging system) may be operated to detect radiation in atleast the second radiation mode. Flow 1700 optionally further includesstep 1576—determining an amount of biological activity corresponding tothe detected amount of radiation in at least the second radiation mode.For example, there may be a correlation between the detected amount ofradiation in at least the second radiation mode and the actual amount ofbiological activity caused by the irradiation in step 1540.Alternatively or additionally, the detected amount of radiation in atleast the second radiation mode may reveal characteristics of thein-situ environment (e.g. a spatial extent of a particular tissue,tumor, or lesion) whereon the amount of biological activity may depend(e.g. the biological activity is specific to a particular tissue, tumor,or lesion). Flow 1500 optionally further includes step 1580, asdescribed above.

Those having skill in the art will recognize that the state of the arthas progressed to the point where there is little distinction leftbetween hardware and software implementations of aspects of systems; theuse of hardware or software is generally (but not always, in that incertain contexts the choice between hardware and software can becomesignificant) a design choice representing cost vs. efficiency tradeoffs.Those having skill in the art will appreciate that there are variousvehicles by which processes and/or systems and/or other technologiesdescribed herein can be effected (e.g., hardware, software, and/orfirmware), and that the preferred vehicle will vary with the context inwhich the processes and/or systems and/or other technologies aredeployed. For example, if an implementer determines that speed andaccuracy are paramount, the implementer may opt for a mainly hardwareand/or firmware vehicle; alternatively, if flexibility is paramount, theimplementer may opt for a mainly software implementation; or, yet againalternatively, the implementer may opt for some combination of hardware,software, and/or firmware. Hence, there are several possible vehicles bywhich the processes and/or devices and/or other technologies describedherein may be effected, none of which is inherently superior to theother in that any vehicle to be utilized is a choice dependent upon thecontext in which the vehicle will be deployed and the specific concerns(e.g., speed, flexibility, or predictability) of the implementer, any ofwhich may vary. Those skilled in the art will recognize that opticalaspects of implementations will typically employs optically-orientedhardware, software, and or firmware.

The foregoing detailed description has set forth various embodiments ofthe devices and/or processes via the use of block diagrams, flowcharts,and/or examples. Insofar as such block diagrams, flowcharts, and/orexamples contain one or more functions and/or operations, it will beunderstood by those within the art that each function and/or operationwithin such block diagrams, flowcharts, or examples can be implemented,individually and/or collectively, by a wide range of hardware, software,firmware, or virtually any combination thereof. In one embodiment,several portions of the subject matter described herein may beimplemented via Application Specific Integrated Circuits (ASICs), FieldProgrammable Gate Arrays (FPGAs), digital signal processors (DSPs), orother integrated formats. However, those skilled in the art willrecognize that some aspects of the embodiments disclosed herein, inwhole or in part, can be equivalently implemented in integratedcircuits, as one or more computer programs ruining on one or morecomputers (e.g., as one or more programs running on one or more computersystems), as one or more programs running on one or more processors(e.g., as one or more programs running on one or more microprocessors),as firmware, or as virtually any combination thereof, and that designingthe circuitry and/or writing the code for the software and or firmwarewould be well within the skill of one of skill in the art in light ofthis disclosure. In addition, those skilled in the art will appreciatethat the mechanisms of the subject matter described herein are capableof being distributed as a program product in a variety of forms, andthat an illustrative embodiment of the subject matter described hereinapplies regardless of the particular type of signal bearing medium usedto actually carry out the distribution. Examples of a signal bearingmedium include, but are not limited to, the following: a recordable typemedium such as a floppy disk, a hard disk drive, a Compact Disc (CD), aDigital Video Disk (DVD), a digital tape, a computer memory, etc.; and atransmission type medium such as a digital and/or an analogcommunication medium (e.g., a fiber optic cable, a waveguide, a wiredcommunications link, a wireless communication link, etc.).

In a general sense, those skilled in the art will recognize that thevarious aspects described herein which can be implemented, individuallyand/or collectively, by a wide range of hardware, software, firmware, orany combination thereof can be viewed as being composed of various typesof “electrical circuitry.” Consequently, as used herein “electricalcircuitry” includes, but is not limited to, electrical circuitry havingat least one discrete electrical circuit, electrical circuitry having atleast one integrated circuit, electrical circuitry having at least oneapplication specific integrated circuit, electrical circuitry forming ageneral purpose computing device configured by a computer program (e.g.,a general purpose computer configured by a computer program which atleast partially carries out processes and/or devices described herein,or a microprocessor configured by a computer program which at leastpartially carries out processes and/or devices described herein),electrical circuitry forming a memory device (e.g., forms of randomaccess memory), and/or electrical circuitry forming a communicationsdevice (e.g., a modem, communications switch, or optical-electricalequipment). Those having still in the art will recognize that thesubject matter described herein may be implemented in an analog ordigital fashion or some combination thereof.

Those skilled in the art will recognize that it is common within the artto describe devices and/or processes in the fashion set forth herein,and thereafter use engineering practices to integrate such describeddevices and/or processes into image processing systems. That is, atleast a portion of the devices and/or processes described herein can beintegrated into an image processing system via a reasonable amount ofexperimentation. Those having skill in the art will recognize that atypical image processing system generally) includes one or more of asystem unit housing, a video display device, a memory such as volatileand non-volatile memory, processors such as microprocessors and digitalsignal processors, computational entities such as operating systems,drivers, and applications programs, one or more interaction devices,such as a touch pad or screen, control systems including feedback loopsand control motors (e.g., feedback for sensing lens position and/orvelocity, control motors for moving/distorting lenses to give desiredfocuses). A typical image processing system may be implemented utilizingany suitable commercially available components, such as those typicallyfound in digital still systems and/or digital motion systems.

Those skilled in the art will recognize that it is common within the artto describe devices and/or processes in the fashion set forth herein,and thereafter use engineering practices to integrate such describeddevices and/or processes into data processing systems. That is, at leasta portion of the devices and/or processes described herein can beintegrated into a data processing system via a reasonable amount ofexperimentation. Those having skill in the art will recognize that atypical data processing system generally includes one or more of asystem unit housing, a video display device, a memory such as volatileand non-volatile memory, processors such as microprocessors and digitalsignal processors, computational entities such as operating systems,drivers, graphical user interfaces, and applications programs, one ormore interaction devices, such as a touch pad or screen, and/or controlsystems including feedback loops and control motors (e.g. feedback forsensing position and/or velocity; control motors for moving and/oradjusting components and/or quantities). A typical data processingsystem may be implemented utilizing any suitable commercially availablecomponents, such as those typically found in datacomputing/communication and/or network computing/communication systems.

All of the above U.S. patents, U.S. patent application publications,U.S. patent applications, foreign patents, foreign patent applicationsand non-patent publications referred to in this specification and/orlisted in any Application Data Sheet, are incorporated herein byreference, to the extent not inconsistent herewith.

One skilled in the art will recognize that the herein describedcomponents (e.g., steps), devices, and objects and the discussionaccompanying them are used as examples for the sake of conceptualclarity and that various configuration modifications are within theskill of those in the art. Consequently, as used herein, the specificexemplars set forth and the accompanying discussion are intended to berepresentative of their more general classes. In general, use of anyspecific exemplar herein is also intended to be representative of itsclass, and the non-inclusion of such specific components (e.g., steps),devices, and objects herein should not be taken as indicating thatlimitation is desired.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations are not expressly set forth herein for sakeof clarity.

The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different othercomponents. It is to be understood that such depicted architectures aremerely exemplary, and that in fact many other architectures can beimplemented which achieve the same functionality. In a conceptual sense,any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality can be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected”, or“operably coupled”, to each other to achieve the desired functionality,and any two components capable of being so associated can also be viewedas being “operably couplable”, to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents and/or wirelessly interactable and/or wirelessly, interactingcomponents and/or logically interacting and/or logically interactablecomponents.

While particular aspects of the present subject matter described hereinhave been shown and described, it will be apparent to those skilled inthe art that, based upon the teachings herein, changes and modificationsmay be made without departing from the subject matter described hereinand its broader aspects and, therefore, the appended claims are toencompass within their scope all such changes and modifications as arewithin the true spirit and scope of the subject matter described herein.Furthermore, it is to be understood that the invention is defined by theappended claims. It will be understood by those within the art that, ingeneral, terms used herein, and especially in the appended claims (e.g.,bodies of the appended claims) are generally intended as “open” terms(e.g., the term “including” should be interpreted as “including but notlimited to,” the term “having” should be interpreted as “having atleast,” the term “includes” should be interpreted as “includes but isnot limited to,” etc.). It will be further understood by those withinthe art that if a specific number of an introduced claim recitation isintended, such an intent will be explicitly recited in the claim, and inthe absence of such recitation no such intent is present. For example,as an aid to understanding, the following appended claims may containusage of the introductory phrases “at least one” and “one or more” tointroduce claim recitations. However, the use of such phrases should notbe construed to imply that the introduction of a claim recitation by theindefinite articles “a” or “an” limits any particular claim containingsuch introduced claim recitation to inventions containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, those skilled in the art will recognize that such recitationshould typically be interpreted to mean al least the recited number(e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that virtually any disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms. For example, the phrase “A or B” will be understood toinclude the possibilities of “A” or “B” or “A and B.”

With respect to the appended claims, those skilled in the art willappreciate that recited operations therein may generally be performed inany order. Examples of such alternate orderings may include overlapping,interleaved, interrupted, reordered, incremental, preparatory,supplemental, simultaneous, reverse, or other variant orderings, unlesscontext dictates otherwise. With respect to context, even terms like“responsive to,” “related to,” or other past-tense adjectives aregenerally not intended to exclude such variants, unless context dictatesotherwise.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting with the true scope andspirit being indicated by the following claims.

What is claimed is:
 1. A method, comprising: identifying a first processthat at least partially converts ionizing radiation to an amount ofoptical energy; identifying a second process that at least partiallyconverts the amount of optical energy to biological activity; responsiveto the identifying a first process and the identifying a second process,determining an amount of ionizing radiation whereby a selected amount ofbiological activity is produced by a combination of the first processand the second process; irradiating at least one region with thedetermined amount of ionizing radiation; detecting an amount of ionizingradiation that is transmitted or forward scattered through at least aportion of the at least one region; and determining an amount ofbiological activity corresponding to the detected amount of ionizingradiation.
 2. The method of claim 1, further comprising: adjusting theirradiating to obtain the selected amount of biological activity.
 3. Asystem, comprising: means for identifying a first process that at leastpartially converts ionizing radiation to an amount of optical energy;means for identifying a second process that at least partially convertsthe amount of optical energy to biological activity; means, responsiveto the means for identifying a first process and the means foridentifying a second process, for determining an amount of ionizingradiation whereby a selected amount of biological activity is producedby a combination of the first process and the second process; means forirradiating at least one region with the determined amount of ionizingradiation; means for detecting an amount of ionizing radiation that istransmitted or forward scattered through at least a portion of the atleast one region; and means for determining an amount of biologicalactivity corresponding to the detected amount of ionizing radiation. 4.The system of claim 3, further comprising: means for adjusting theirradiating to obtain the selected amount of biological activity.
 5. Asystem, comprising: circuitry for identifying a first process that atleast partially converts ionizing radiation to an amount of opticalenergy; circuitry for identifying a second process that at leastpartially converts the amount of optical energy to biological activity;circuitry, responsive to the circuitry for identifying a first processand the circuitry for identifying a second process, for determining anamount of ionizing radiation whereby a selected amount of biologicalactivity is produced by a combination of the first process and thesecond process; circuitry for irradiating at least one region with thedetermined amount of ionizing radiation; circuitry for detecting anamount of ionizing radiation that is transmitted or forward scatteredthrough at least a portion of the at least one region; and circuitry fordetermining an amount of biological activity corresponding to thedetected amount of ionizing radiation.
 6. The system of claim 5, furthercomprising: circuitry for adjusting the irradiating to obtain theselected amount of biological activity.